The temple complex at Koh Ker, northeast of Siem Reap, represents the remnants of the capital of the Khmer Empire from 928 AD. - 944 A.D. under the then King Jayavarman IV and his son Hasavarman II. The Koh Ker site is dominated by Prasat Thom, a 30 meter tall temple mountain raising high above the plain and the surrounding forest. Great views await the visitor at the end of an adventurous climb. Across the site of Koh Ker there are many Prasat or tower sanctuaries, including several Lingas.